The calculations of basic and diluted EPS are based on the weighted average number of shares of common stock and potential common stock outstanding during the period. Diluted EPS includes the incremental effects of the various long-term incentive compensation plans and ATM forward sale agreements under the treasury stock method when the impact would be dilutive (See Note 6, "Equity,"). For the purposes of determining diluted EPS, for the three and nine months ended September 30, 2023, the shares underlying the purchase contracts included within the Equity Units were included in the calculation of potential common stock outstanding using the if-converted method under US GAAP and we assumed share settlement of the remaining purchase contract payment balance from our Equity Units based on the average share price during the period. A numerator adjustment was reflected in the calculation of diluted EPS for interest expense incurred in the three and nine months ended September 30, 2023, net of tax, related to the purchase contracts. The purchase contracts were settled on December 1, 2023.

We began using the two-class method of computing earnings per share in 2023 because we have participating securities in the form of non-vested restricted stock units with a non-forfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator.


	Three Months Ended September 30,				Nine Months Ended September 30,
(in millions, except per share amounts)	2024		2023		2024		2023
Numerator:
Net Income Available to Common Shareholders	$	85.7	$	77.0	$	515.8	$	436.1
Less: Income allocated to participating securities	0.2		0.1		0.9		0.3
Net Income Available to Common Shareholders - Basic	85.5		76.9		514.9		435.8
Add: Dilutive effect of Equity Units	—		0.4		—		1.2
Net Income Available to Common Shareholders - Diluted	$	85.5	$	77.3	$	514.9	$	437.0
Denominator:
Average common shares outstanding - Basic	451.9		413.5		449.4		413.2
Dilutive potential common shares:
Equity Units purchase contracts	—		33.1		—		31.9
Equity Units purchase contract payment balance	—		0.6		—		1.2
Shares contingently issuable under employee stock plans	0.9		0.7		0.9		0.7
Shares restricted under employee stock plans	0.3		0.4		0.3		0.4
ATM forward sale agreements	1.4		—		0.8		—
Average Common Shares - Diluted	454.5		448.3		451.4		447.4
Earnings per common share:
Basic	$	0.19	$	0.19	1.15		1.05
Diluted	$	0.19	$	0.17	1.14		0.98